A guide to simplifying invoicing with this open source tool: 
Many IT projects are late, over budget, and subject to dramatic changes during development. This makes invoicing for them one of the most taxing activities in IT. It’s stressful—it involves dealing with ambiguities, conflicting interests, and human error. Worse, every single decision made during the project affects how much you can bill for. When a sales guy brags—incorrectly—that your software “includes this feature,” you can’t invoice for the time to build it. When a support guy admits something is a bug rather than an imprecise spec, you won’t be able to charge money for it.
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